<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{width:100px;
        height: 100px;
        background-color:red;
        margin: 10px;
        color:white;
        }
        /* div:nth-child(2){
            display: none;
        } */
        /* div:nth-child(2){
            visibility: hidden;
        } */
        td{
            width: 100px;
            height: 30px;
            border: 1px solid black;
        }
        table{
            border-collapse:collapse;
        }
    </style>
</head>
<body>
    <table border-collapse="collapse">
        <caption>学生信息表</caption>
        <colgroup>
              <col style="background-color: red;">
              <col style="background-color:blue;">
              <col style="background-color:pink ;" span="2">
              <!-- <col style="background-color:yellow;"> -->
        </colgroup>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
    </table>
    <div>div1</div>
    <div>div2</div>
    <div>div3</div>
</body>
</html>